A new study has found that long-term stimulant abuse had more significant effects on brain volume in women compared with men.

The researchers sought to determine how the brains of people previously dependent on stimulants were different from the brains of healthy people. 

The researchers analyzed structural brain magnetic resonance imaging exams in 127 men and women, including 59 people (28 women and 31 men) who were previously dependent on cocaine, amphetamines and/or methamphetamine for an average of 15.7 years, and 68 people (28 women and 40 men) who were similar in age and were not previously dependent on those drugs.

"We specifically wanted to determine how these brain effects differed by gender," said Jody Tanabe, MD, professor of radiology at the University of Colorado School of Medicine. "While the women previously dependent on stimulants demonstrated widespread brain differences when compared to their healthy control counterparts, the men demonstrated no significant brain differences." 

The women who were former stimulant abusers showed significant loss of gray matter volume in their brains, while men who were former stimulant abusers demonstrated no significant brain differences compared to their healthy counterparts.

The researchers looked at how these brain volume differences were related to behaviors. In women who were previously dependent on stimulants, there were vast changes in brain structures that are important for decision making, emotion, reward-processing and habit formation.

"The gray matter volumes in women who had been stimulant dependent correlated with more impulsivity, greater behavioral tendencies to approach to reward, and also more severe drug use," Tanabe said. "In contrast, all men and healthy women did not show such correlations."

The findings may provide a clue to the biological processes underlying the clinical course of stimulant abuse in men and women. "We hope that our findings will lead to further investigation into gender differences in substance dependence and, thus, more effective treatments," Tanabe said.

The results were published online in the journal Radiology. The study was supported by grants from the National Institute on Drug Abuse. Other authors from the University of Colorado Anschutz Medical Campus were Michael Regner, MD, Manish Dalwani, MS, Dorothy Yamamoto, PhD, Robert Perry, MD, Joseph Sakai, MD, and Justin Honce, MD.